This is a work in progress. It compiles and is able to do basic command
dispatch, including git autocorrection, while using optparse-applicative
for the core commandline parsing.
* Many commands are temporarily disabled before conversion.
* Options are not wired in yet.
* cmdnorepo actions don't work yet.
Also, removed the [Command] list, which was only used in one place.
Seen for example, a newly checked out git submodule. In this case,
.git/HEAD is a raw sha, rather than the usual reference to a ref.
Removed currentSha in passing, since it was a more roundabout way of
doing what headSha does, and headSha is more robust.
This allows bypassing the direct mode guard in a safe way to do all sorts
of things including git revert, git mv, git checkout ...
This commit was sponsored by the WikiMedia Foundation.
